1. Field of the Invention
The invention relates to microstructure elements and to a process for the production of microstructure elements from a metal, plastic or sintered material.
2. Discussion of the Background
Microstructure elements have dimensions in the micron range; they are required, in particular, in precision engineering, micromechanics, microoptics and microelectronics, for example as sensor elements, actuator elements or components in fluid or electronic systems. They are generally employed where properties such as low bulk, low weight and inexpensive manufacture are required. The invention has the object of providing microstructure elements of this type in an economic manner.
It is known that microstructure elements can be produced from plastic, metal or ceramic by the LIGA process by lithography, electroforming and casting. See Kernforschungszentrum Karlsruhe, Report 3995 (1985). Plastic microstructure elements are obtained inexpensively and in large numbers by multiple casting from a metallic mold insert by reaction injection molding or injection molding.
The primary structure is obtained by imagewise irradiation of a radiation-sensitive plastic with X-rays or synchrotron radiation, followed by dissolution of the irradiated (or unirradiated) areas of the plastic. The mold insert is produced by electrodeposition of metal in the pre-dissolved areas of the primary structure. The structure of the mold insert is complementary to the primary structure. In spite of all the advantages offered by the LIGA process, such as, for example, substantial geometric freedom in a plane and the wide variety of materials that can be employed, simpler processes are desired in many cases.
It is furthermore known that crystalline materials can be structured by anisotropic etching (Proceedings of the IEEE, Vol. 70 (1982), No. 5, and IEEE Trans. Electron. Devices (ED-25 (1978), No. 10, 1178-1185)). The resultant microstructure elements can only rarely be used directly, since the etched material does not satisfy certain requirements--for example adequate breaking strength.